Series boiler and method of operating the same



Aug 27, 1929- D. s. JAcoBUs 3,5923- SERIES BOILER AND METHODI OF OPERATING THE SAME Original Filed April f1.6,y 1918 4 Sheetshe't 1 4 Sheets-Sheet 2 41 l l IV iulrllnW |v III h flHrl l S. m m l. um, 1 11 w J N E R he WJ. fm w A ,b MK v. A @mmm zmxa h f. Y \,w\ li SERIES BOILER AND METHOD OF OPERATING THE SAME Original Filed April 16, 1918 Aug@ 27, 1929s, D., s., JACQEU SERIES BOILER AND METHOD OF OPERATING THE SME original Filed April 16, 191e 4 Sheets-Sheet 5 m m mm1 E -W i f l INVENTOR.

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Aug., 27, 929 D, 5 JACQBUS SERIES BOILER AND METHOD OF PERTING THE SAME original Filed April 16 1918 4 sheetsheet 4 INVENTOR.

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Patented Aug. 27, 1929.

UNITED STATES PATEISITl OFFICE.

DAVID s. JAcoBUs, or JERSEY cITY, NEW JERSEY, AssrGnoE To THE' yiaancooir a WIL- COX COMPANY, OF BAYONNE, NEW

JERSEY, A CORPORATION'OF NEW JERSEY.'

SERI'ES BOILER AND METHOD 0F OPERATING- THE SAME.

This invention relates to series boilers and methods of operating the same.

Fig. l is a diagrammatic sectional side eleration showing one form of my improved boiler provided with a hand-fired coal furnace and showing, also, feed Water apparatus.

and superheat limiting apparatus; Fig. 1a is a horizontal section taken through thetank 12 just above the float 21; Fig. 1* is a section taken along the plane of the line 1*--1b of.F ig. 1"; Fig. 2 is adetail of the regulating valve controlling steam for drivingthe feed pumpin Fig. 1; Fig. 3 is'a view similar to Fig. 1, showing my improved boiler provided with an underfeed Stoker-this view also showing a superheat limiting device and also a device for regulating the temperature of the superheated steam; Fig. ais an enlarged sectional view through the relief valve 129; Fig. 3b is a section-taken on the plane of the line 3b-3b of Fig. 3; Fig. 4 is a view similar to Fig. 1, showing a modified form of the boiler with its units arranged in a different relation; Fig. 5 is a sectional side elevation of my improved boiler showing oiltiring and arranged for practical use as regards the preferred general proportions of headers and tubes, although the view is partially diagrammatic; Fig. 6 is a partial end elevation of a portion of. F ig.'5, showing the supporting of the header boxes.

My invention relatesto forced circulation series boilers and the method of operating the same, and is designed to provide an iinproved boiler of this type, on which I have with tubes, preferablv of U-fo'rm, extending upwardly therefrom. y The present application, which is a division of my prior application Serial No. 228,827. which was filed in the Patent Otlice on or about April 16, 1918, relates more particularly to the feeding system including the Steam and water drum, which acts as a steam separating drum or tank, and the parts associated therewith, including connections for leading steam and water thereto from the series boiler, and means for feeding water .rom said drum, and to the method of operating a boiler of this type. IVater is passed by forced circulation through tubes in series,

andthe feed water for theboiler is controlled and this application filed .Tune 19,

by the level of the Xvater in the. separating drum or tank.

In the forms of Figs. 1 to 4, inclusive, the I header boxes are shown much larger and the U-tubes much shorter than I prefer to employ in. practice, for clearness of illustration of the principles involved. I In Fig. 1, 2 represents the header boxes and 3 the series of U-shaped tubes extending upwardly therefrom, the boxes being preferably transverse to the flow of the gases and protected therefrom by the refractory bottom 4 of the furnace chamber.,` In this form of Fig. 1,',theV portion A is made up of the tubes'most remote from the source of heat, which is indicated as a furnace 5 having a hand-fired grate 6. B indicates tubes nearer the source of heat than the tubes A and C represents the superheater tubes, which, in this form, are nearest the source of heat, 7 being the oiftake flue for the gases.. The hottest gases flow over the hottest heating surface and the coldest gases over the coldest surface, thereby embodying the ,so-called counter-flow principle.

The feed Water enters the boiler through the pipe 8 leading into the rearmost header box. T is Water flows thence through the U-shape tubes and the successive boxes of the series 4toward the furnace end, passing as Water and, after steam is generated, as combined, steam and Water, forwardly through the successive boxes and tubes to the header 9, Which is the foremost header of the boiler tubels proper. From this header 9 the steam, wit down through a pipe 11 into a tank 12, the pipe 11 having a hand-controlled valve 13. The pipe 11 also has a cross-over pipe, provided with a hand-controlled valve 14 and leading to a. pipe 15 which conducts the steam from the tank to the rear-'header 16 of the superheater. The pipe 15 also, has a handcontrolled valve 17. header 16 the steam fiows through the U- tubes into the exit header 18, from which it flows through the outlet pipe 19.

The water fed tO-the boiler is controlled in the following manner:

`The feed pipe 8 is provided with a loop adjacentto the tank 1 2, this loop having a valve, shown at 20, controlled by a float 2l lying on the body of Water in this tank. Tlu` .shaft of the float-lever extends through a From the supcrheater in detail in Fig. 2. This valve is controlled shown in Fig. 2, an

stuffing-box in the'side ofthe tank and is eonnected tothe valve-stemiof the valve or cock 20. Should the Water level fall in the 'tank 12, more feed water is admitted through the pipe 8 into and through the series boiler,

which will restore the water level in the tank'. y Should the Water level rise in' the tank, the

supply of feed water will be reduced and the level will correspondingly fall in the tank 12. The feed water is forced into the boiler by a pump 22, to which water is supplied" from the tank 23 through the pipe 24, makeup water being supplied to the tank 23 through the valved pipe 25". The steam for the feed pump enters through pipe 25, having a diaphragm-controlled valve 26, shown by the pressure in the Water feed pipe 8, which has a branch 27 provided with a pressure gauge 28 and leading to one side of the fiexible diaphragm 29. The pressureon vthis diaphragm is resistedby a spring 3Q bearing against the plate 31, which acts on the center of the diaphragm. The spring 30 surrounds the stem of the control valve 26 for the steam inlet pipe 25. By making the spring of proper strength, the valve may be arranged to close at they pressure desired on the exit side of the feed pump, which pressure is transmitted to the side of the dlaphrag'm opemployed to maintain a reasonable-uniform pressure of discharge on the water from the pump. I may use a diaphragm-controlled valve so arranged that the pressure of the water being pumped can be varied' at will by adjusting the valve, such a valve being an ordinary commercial product.

The final header 9 of the boiler is preferably provided with a safety valve, shown in -Fig. 1 at 33, and the outlety pipe 19 from the superheater 18 is preferably provided with a branch 34 having a safety valve 35 and a stop valve 36. The stop valve is used in starting up the boiler and to maintain a circulation through the boiler in case of a sudden shut-down.

I have also shown, in Fig. 1, a superheat limiting apparatus. In this form, the steam from the pipe 19 flows through -a pressure regulating valve 37 and a stop valve 38, which is Wide open under normal conditions, and thence down through the chamber 39 over of a feed pump may be thecoil 40 of a superheat limiting device, and thenceto supply pipe 41, which passes to any desired apparatus.

The pressure generated in the coil 40 acts upon the superheat limiting device, generissued on or about January 27, 1920. v

In Fig. 1 this device acts by admitting cold air to the interior of the boiler setting in case the superheat exceeds a certain predetermined figure. This air is admitted through the doors 42, which in the figure are indicated as open-the arrows showing the infiow ofair therethrough.

The superheat limiting device acts only in case of excessive superheat, the amount of superheatbeing. normally such that the doors 42 are closed and no air is admitted through these door openings into the setting. The surface of the superheater C is so formed that the superheat will be normally below a figure which will give trouble. In case of a sudden shut-down, or any'other irregularity in operation which would lead to excessive superheat, the superheat limiting device D is brought into action in the same way as the safety valve on a steam boiler is called into action when the steam pressure exceeds that ally indicated at D, and which is fully dev scribed 'in my Patent No. 1,328,997, which was heat limiting device herein shown is a safety device for preventing excess superheat and is not a device for regulating theamount of superheat.

In starting up such a series boiler from a cold condition, all parts of the boiler, includ; ing the superheater, are filled with water under pressure. The air Within the boiler need not be removed, butl by feeding in water at a high pressure the volume of air pocketed in the boiler is comparatively small.

valves 13 and 17 are slowly `valve 14 closed. The water Some water is preferably allowed to flow through the boiler before startingto remove a portion of the air which would otherwise be pocketed, this water being allowed vto escape through the stop valve 36.

At this time, when the apparatus is flooded with water preparatory to starting, the valves 13 and 17 are closed and the valve 14 is open. After steam is formed, steam and water are allowed to escape through the valve 36.

y`When the flow of steam and water throu h the valve-36 becomes reasonably uniform, t 1e ofpened and the ed Aduring the period lof starting up is regulated by means of the feed valve 128. In starting up,`the water is maintained at such a level inthe tank 12 that the valve 20 which is controlled by the float 21 remains open, the `Water level pipe 11- to be governed by the amountof water which is allowed to iow from the bottom of thetank through a pipe fitted with the throttle valve 45 and into the feed tank 23. By adjusting the throttle valve 45, the water may be blown from the tank 12 at any desired rate and with the Water in the tank 12 maintained at a constant level, the Water in the steam, which enters the tank 12, will enter the tank at the same rate as the water is blown away from the tank 12. The tank 12 is fitted with a blow-off connection 44 to remove any sediment accumulating in the tank and to drain the tank 12.

It will thus be apparent that my series boiler operates on a closed circuit, the water, which is withdrawn from the separating tank 12 at a predetermined constant rate, Which is regulated by the valve 45, passing into a 1 e` serve tank 23, to which the make-up water is supplied. The reserve tank 23 thus consti'- tutes a source of 'water supplementing the amount that is withdrawn from the tank 12 and the amount that is fed to the boiler.

In operating the boiler, the pressure is kept within the desired range in the feed pipe, the pressure being indicated by the pressure gauge 28. The frictional resistance of the water and steam flowing through the series boiler is a material factor, and the pressure of the feed water entering through the pipe 8 mustV be suh'iciently high to overcome the frictional resistance of the flow. This frictional resistance varies greatly, increasing with the load, and the pressure of the feed water entering through the pipe 8 ma be varied in accordance with the conditions under which the boiler may be operating. The steam and water from the box 9 enters the tank 12 where the two separate, and the steam passes up through the valve 17 to the header box 16 of the superheater and thence through the superheater limiting system to-the point of offtake.

In Fig. 3 I show a form similar to that of Fig. 1, the similar parts being marked with theV same numerals with the letter a applied, the underfeed Stoker 46 being employed.

In this figure I also show the coil 40a of the superheat limiting device as placed in the outlet pipe 19a of the superheater.

In this figure I also show an additional feature, consisting of the superheated steam attemperating device marked 47, which acts to regulate the temperature of the superheated steam discharged from the supe-rheater. This attemperating device is similar to one shown in my Patent No. 1,149,265, dated August 10, 1915, for method of and apparatus for regulating the temperature of superheated steam.

The attemperator admits a regulated amount of water in the superheater through the valve 4S and smaller pipe connections 49,.

pipe 50 by opening and closing a stop cock 53, being governed through the temperature of the superheated steam surroundingv the coil 40. The superheat limiting device Da is not brought into action eXcept when through some unusual circumstance the superheat becomes higher than it should be, in which case cold air is admitted to the setting as before andthe damper 54 is closed` this damper admitting forced blast to the Stoker.

In this form, a float valvel55 of any well known form is attached to the outlet of the pipe 25a to regulate the amount of- Water supplied to the. feed tank. I also show three sets of superheater tubes, the intake ends of the tubes being extended down near the bottoms of the headers, shown at 56, to reduce the amount ofwater that would tend to pocket in the superheater headers.

In this figure I show a diaphragm controlled-valve 26a attached by the pipe 27a to the discharge pipe leading from the feed pump. The function of the diaphragm controlled-valve 2Gn is the same as that of the valve 26 in Fig. 1. A relief vvalve 129 is placed on the discharge side of the feed pump and in case of the closure of the float-oper- 'ated valve 20a, resulting in 'an over-pressure',4 it by-passes some of the water back to the feed tank 23. The speed of'the pump may be regulated by hand in. starting up the boiler by adjusting the throttle and stop Valve G in the steam pipe leading to the pump. y

In Fig. 4 I show a form in which the boiler portion of the tubes Bd is divided into two parts, one part acted upon by the hot-test gases and the other by the gases after they have passed the superheater portion Cd.

In this ligure the separator. tank 12d is shown as a horizontal cylinder or drum. and

Athe amount of feed water admitted to the boiler through the pipe 8d is regulated by a feed regulating device 64 of Well known construction, so as to maintain an approximately constant level of water in the tank 12d. The water from the tank 12d in this form passes through the valved pipe 45d to the feed tank 23d, a coil 65 being used to transmit the neat from the Water passing from. the tank 12d into the feed tank 23 and prevent lossV of heat through the vapor escaping from the point lISU plied, the boiler portion being divided intoA two sections Be with the superheater Ce between them; so that. the hot gases from the' furnace contact with a portion of the boiler orevaporating tubes, thence over the superheater tubes, thence over further boiler tubes, and thence over the economizer tubes Ac, before reaching the uptake 7e. The oil' burners 66 may be spaced along the front of the furnace, a part of which is broken away in the drawing.

In this form, the feed water in the pipe 8e enters the rear header box 2, and thence flows upwardly through the tubes 3e, and thence downwardly to the header box 67. From this header box the water then flows upwardly through tubes 68 into the header 69. The headers 69 are at a slightly higher level than the headers 67, and the tubes 68 are spaced alternately with reference to the downtake tubes leading into the header box 67. The succeeding arrangement is similar, the down-flow tubes being spaced alternately with the up-flow tubes of each box until the header 70 is reached. From this header the steam and water flows through tubes 7l which have wider bends bridging the superheater tubes and entering the header 72. FromY the header 72 the steam and water flows progressively through the boiler tubes and finally enter the header 9e. From this header the steam and water pass through a series of pipe connections 73 into a cross-pipe 74. The water is separated from the steam in this cross-pipe, and the water flows through one or more small pipe connections 75 (only one being shown) through the valved connection 76 and to the tank 12. From the separating pipe 74 the steam, from which the greater part of the water has been separated, passes upwardly through the small pipes 77 into the superheater header 78. From this header the steam passes through the super-heater tubes into the superheatcr header 74', from which it is taken away. The water is maintained at an approximately constant level in the tank 12e by any of the means thus far described, a certain amount of water being allowed to continuously escape through the throttle valve for the purpose previously set forth.

The preferred method of supporting the tubes in the headers is illustrated in Fig. (i,

port-ing pieces 79 may'interfere with the removal of the fittings opposite the ends of the tubes if it is necessary to remove those adjacent Ato these supports. In such case, the bolts for one of the pieces 79 are removed with the piece, after which the fittings can be more readily manipulated. Each header is supported by more than one of the pieces 79, so that one piece may be removed without interfering with the header support. If necessary, the headers can be jacked upwardly in order to replace the supporting pieces 79.

The withdrawalof steam and water to a separating tank or vessel, in which.` the water is separated from the steam, is-'animportant feature.x Where a superheater is used, the steam is thus taken in a comparatively dry state to the superheater. The provision of this tank makes it possible to cari'y a much more uniform degree of superheat and a more uniform pressurethan could be ob-4 tained without the separating receptacle. The tank also serves a useful purpose where there are impurities in the water, as the steam free, or practically free from the impurities, flows from the separating tank into the superheater, the impurities collecting in the water. l

Bleeding the water from the steam and water drum or separating tank is also an important feature, as it permits of a re-cir' culation of such water through the tubes with or without fresh make-up water. As a consequence the water fiowing through thetubes v'is all pump circulated and .its amount is always in excess of what can be evaporated to an extent regulated by the bleeding. This makes it sure that no tube even in the hottest zone can become overheated in normal operation.

The action secured through bleeding out a certain amount of water from the steam and water drum is as follows: I

To maintain a given height of feed water in the drum, the feed` must be adjusted so that it will correspond to the steam'evaporated plus the water drawn out from the drum. If the rate at which the water is fed is too low, the, water level will fall, through the water being bled away from the drum, and if too great, the water level will v`ri se, through more water being fed into the drum than is bled away from the drum.

Should no water be bled away from the drum, there would be no variation in the water level in the drum except that caused through over-feeding the boiler, which would result inthe water level rising in the drum, and after rising in the drum, the water level would not fall even should too little water be fed to the boiler. The draining off of a regulated amount of water from the steam and water drum is, therefore, a most important feature, as it makes possible the control of the feed water through a regulator which acts through variation in theheight of the water in the drum, and also makes possible the feeding of sufficient water to the boiler tubes to have an excess of water going through them over and above that which is vaporized in the .-tubes, thus obtaining saturated steam at the outlet with the water. The feed-water regulators used in connection with ordinary steam boilers are in the main operated through variation in water level in the boilers, and by providing a series boiler where the feed water can be controlled through the means of a variation in the water level of a separator tank, it is possible to employ standard apparatus for the purpose.

In the foregoing description and the appended claims, I have used the term feed water to designate the water fed to the boiler tubes and the term make-up water to designate the water added from an outside source to the volume of water from which the feed water is taken.

What I claim and desire to secure by Letters Patent of the United States is:

l. In the operation of a series boiler, the steps consisting of withdrawing mingled steam and water from the boiler, separating the water from the steam, maintaining a pool of the separated water, continuously removing a substantially uniform amount of water from the pool, forcing an amount of feed water sufiicient to provide for the steam evaporated inthe series boiler and for the amount of water removed from the pool into and forwardly through the tubes of the series boiler by power exterior to the boiler, and controlling the feed of water to the boiler by the level of water in said pool.

2. In the operation of a series boiler, the steps consisting of withdrawing mingled steam and water from the boiler, separating the water from the steam, maintaining a pool of the separated Water, continuously removing a substantially uniform amount of water from the pool, forcing an amount of feed water sufficient to provide for the steam evaporated in the series boiler and for the amount of water removed from the pool into and forwardly through the tubes of the series boiler by power exterior to the boiler, utilizing variations in the water level in the'pool to control th'e feed of water to the boiler, and utilizin heat in the water removed from the pool to Iieat the feed water.

3. In the operation of a series boiler, the steps consisting of withdrawing mingled steam and water from the boiler, separating the water from the steam, maintaining a pool of the separated water, continuously removing a substantially uniform amount o'f water from the pool, forcing an amount of feed water sufficient to 'provide `for the steam evaporated in the series boiler and for the amount of water removed from the pool into and forwardly through the tubes of the series boiler by power exterior to the boiler, utilizing variations in the water level in the pool to control the feed of water to the boiler and returning the water withdrawn from the pool to the boiler.

4. In the operation of a series boiler, the steps consisting of withdrawing mingled steam and water from the boiler, separating the water from the steam, maintaining a pool of the separated water, continuously removing water from the pool, forcing an amount of feed water sufficient to provide for the steam evaporated in the series boiler and for the amount of water removed from the pool into and forwardly through the tubes ofthe series boiler by power exterior to the boiler, and utilizing heat in the water removed from the pool to heat the feed water.

5. In the operation of a series boiler, the steps consisting of withdrawing mingled steam and water from the boiler, separating the water from the steam, maintaining a pool of the separated water, withdrawing a regulated amount of water from said pool, mingling make-up water with the water wit-hdrawn from the pool and conducting the mingled water to the boiler, and automatically increasing or decreasing the iow of mingled water in response to a respective rise or fall of the water level in the pool.

6. In the operation of a series boiler, the method of forcing water through the boiler at such a rate that only a portion of it is converted into steam, continuously withdrawing the mingled steam and water from the boiler, separating the water from the steam to form a pool, withdrawing water from the pool, mingling make-up water with the water withdrawn from the pool, conducting the mingled water to the boiler and automatically increasing or decreasing the flow of the mingled water to the boiler in response to a respective rise or fall of the Water level in the pool. i

7. In the operation of a series boiler, the steps consisting of withdrawing mingled steam and water from the boiler, separating the water from the steam, maintaining a pool of the separated water, continuously withdrawing water from the pool, mingling makeup water with the water withdrawn from the pool, conducting the mingled water to the boiler, and automatically controlling the supply of water to the boiler to produce the same amount of water at the exit of the boilerias is withdrawn from the pool.

8. The method of operating a series boiler which consists in causing water to issue from the boiler with the steam, separating the water from the steam to form a pool, withceptacle for controlling the rate of drawing aregulated amount of water from said pool, mingling make-up water with the water withdrawn from the pool, conducting the mingled water to the boiler, utilizing the matically increasing or decreasing the flowy of water to the boiler in response to a respective rise or fall of the water level in said pool. i l

10. The method of operating a series boiler which consists in causing water to issue from the boiler with the steam, separating the water from the steam and forming a pool of water, withdrawing water from said pool, mingling make-upi water with the water withdrawn from said pool, conducting the mingled water to the boiler and automatically increasing or decreasing the flow of mingled water in response to a respective rise or fall of the water in said pool.

11. ln a series boilerveomprising stea generating tubes, a receptacle,`eonnections for conducting steam and water from the generating tubes to said receptacle, means for continuously removing from said receptacle aV substantially uniform amount 'of water, means for forcing an amount of feed water sulicient to provide for the steam evaporated in the series boiler and for the amount of water removed from the receptacle into and forwardly through the tubes of the series boiler by power exterior to the boiler, and means operable by conditions within the refeed of the feed water to the boiler.

12. ln a series boiler comprising steam generating tubes, a receptacle, connections for conducting steam and water from the generating tubes to said receptacle, means for continuously removing from said receptacle a substantially uniform amount of water, means for forcing an amount of feed water sufficient to provide for the steam evaporated in the series boiler and for the amount of water removed from the receptacle into and forwardly through the tubes of the series boiler by power exterior to the boiler, means responsive to conditions within the receptacle for controlling the rate of feed of the feed water to the boiler, and means 'for utilizing the heat in the water removed from the receptacle to heat the feed water' 13. In a series boiler comprising steam generating tubes, a receptacle, connections for conducting steam and water from the generating tubes to said receptacle, means for con tinuously removing water from the receptacle, means for forcing an amount of feed water sufcent to provide for the steam evaporated in the series boiler and for the amount of water removed from the receptacle into and forwardly through the tubes of the series boiler by power exterior to the boiler, and means operable by conditions within ythe receptacle'for controlling the rate of feed of the feed water to the boiler.

14. ln a series boiler comprising steam generating tubes, a receptacle, connections for conducting steam and water from the generating tubes to said receptacle, means for continuously removing from said receptacle a substantially uniform amount of water, means for` forcing an amount of feed water suicientto provide for the steam evaporated inthe series boiler and for the amount of water removed from the receptacle into and forwardly through the tubes of the series boiler by power exterior to the boiler, means responsive to conditions within the recep taele for controlling the rate of feed of the feed water to the boiler, and connections for supplying the water withdrawn from said receptacle to said second-named means.

15. in a series boiler comprising steam generating tubes, a receptacle, connections for conducting steam and water from the generating tubes to said receptacle, means for continuously removing from said receptacle a substantially uniform amount of water, means for forcing an amount of feed water suliicient to provide for the steam evaporated in the series boiler and. for the amount of water removed from the receptacle into and forwardly through the tubes of the series boiler by power exterior to the boiler, means responsive to the water level in said receptacle for controlling the rate of feed of water to the boiler, `and means for utilizing the heat in the water removed from the receptacle to heat the feed water.

16. ln combination, a steam boiler, means for feeding water to said boiler, a steam and water separating tanlgeonnections for carrying the steam and water from said boiler to said tank, means for withdrawing water from' said tank, means for mingling make-up water with the water withdrawn from said tank, means for conducting the mingled water to the boiler, means for controlling `elle water supplied'to the boiler in accordance with the water level in said tank, and means independent of the water/level in said tank for withdrawing steam therefrom.

17. In combination, a steam boiler, means for feeding water to said boiler, a steam and water separating tank, connections for carrying the steam and water from said boiler to said tank, means for withdrawing water from said tank, means for mingling makefup llO mamar water with the water withdrawn from said tank, means for conducting the mingled water to the boiler, a float-operated valve actuated by the water in said tank for controlling the flow of water to the boiler, and means independent of the water level'insaid tank for withdrawing steam therefrom.

18. A series boiler havirig a separating tank or vessel, means for maintaining water at a certain level therein including a connection leading steamand water from the boiler to said vessel, means for regulating the feed to the tank 'in accordance withV the water level in said tank, and means for bypassing the vessel in starting the boiler.

19. A series boiler having a separating tank or vessel, means for maintaining water at a certain level therein including a connection leading steam and water from the boiler to said vessel, means for regulating the feed to the tank in accordance with the water level in said tank, means for bypassing the vessel in starting the boiler, and an adjustable steam outlet arranged to blow off steam and water in starting up the boiler.

20. In a series boiler having a closed Circuit and comprising steam generating tubes, means for forcing a mixture of steam and water through the generating tubes, a tank, connections for conducting the steam and water from the generating tubes to said tank, the water being separated from the steam in said tank, means for continuously Withdrawing from the separating tank a uniform amount of water, means for mingling makeup water with the water withdrawn from said tank, means for conducting the mingled water to the boiler, and means independent of the amount of water in said tank for withdrawing steam therefrom.

21. In a series boiler having a closed circuit and comprising steam generating tubes, means for forcing a mixture of steam and water through the generating tubes,- a tank, connections for conducting the steam and water from the generating tubes to said tank, the water being separated from the steam in said tank, means for continuously withdrawing from the` separating tank a uniform amount of water, means for mingling makeup water with the water withdrawn from said. tank, means for returning the mingled water to the boiler, means for regulating the .amount of mingled water conducted to the` 22. The method of operating a forced circula-tion series boiler which comprises forcing water thereinto in excess of the amount evaporated, separating the steam and water issuing therefrom, and recirculating the separated water through the boiler along the same path with the incoming make-up water by power exterior to the boiler.

23. The method of operating a forced circulation series boiler which comprises forcing water thereinto in excess of the amount evaporated, separating the mixture of steam and water issuing therefrom, mixing the separated water with make-up water, and forcing the two together into said boiler along the same path bypower exterior to the boiler.

24. In the operation of a series boiler, the steps consisting of withdrawing mingled steam and water from the boiler, separating the water from the steam, maintaining a pool of the separated water, continuously removing water from the pool and forcing an amount of make-up water sui'icient to provide for the steam evaporated in theseries boiler and for the amount of water removed from the peol into and forwardly through the tubes of the series boiler by -powerexterior to the boiler..

25. In combination, a steam boiler, means for feeding water to saidboiler, a steam and waterseparating tank, connections for carrying the steam and water lfrom said boiler to said tank, means for withdrawingwater from said tank, means for mingling make-up water with the water withdrawn 'from said tank, and a single pump for forcing the mingled water into the boiler.

DAVID s. Jaoous.. 

